`NH_(3)(g)+3Cl_(2)toNCl_(3)(g)+3HCl(g),DeltaH_(1)`
`N_(2)(g)+3H_(2)(g)to2NH_(3)(g),DeltaH_(2)`
`H_(2)(g)+Cl_(2)(g)to 2HCl(g),DeltaH_(3)`
The heat of formation of `NCl_(3)`(g) in the terms of
`DeltaH_(1),DeltaH_(2),DeltaH_(3)` is :
A. `DeltaH_f=-DeltaH_(1)+(1)/(2)DeltaH_(2)-(3)/(2)DeltaH_(3)`
B. `DeltaH_(f)=DeltaH_(1)+(1)/(2)DeltaH_(2)-(3)/(2)DeltaH_(3)`
C. `DeltaH_(f)=DeltaH_(1)-(1)/(2)DeltaH_(2)-(3)/(2)DeltaH_(3)`
D. none of the above
